Contrast-enhanced CT and Acute Kidney Injury: Risk Stratification by Diabetic Status and Kidney Function

Background: Diabetes mellitus may be associated with an increased likelihood of CT contrast material-induced acute kidney injury (CI-AKI), but this has not been studied in a large sample with and without kidney dysfunction. Purpose: To investigate whether diabetic status and estimated glomerular filtration rate (eGFR) are associated with the likelihood of acute kidney injury (AKI) following CT contrast material administration. Materials and Methods: This retrospective multicenter study included patients from two academic medical centers and three regional hospitals who underwent contrast-enhanced CT (CECT) or noncontrast CT between January 2012 and December 2019. Patients were stratified according to eGFR and diabetic status, and subgroup-specific propensity score analyses were performed. The association between contrast material exposure and CI-AKI was estimated with use of overlap propensity score-weighted generalized regression models. Results: Among the 75 328 patients (mean age, 66 years ± 17 [SD]; 44 389 men; 41 277 CECT scans; 34 051 noncontrast CT scans), CI-AKI was more likely in patients with an eGFR of 30-44 mL/min/1.73 m2 (odds ratio [OR], 1.34; P < .001) or less than 30 mL/ min/1.73 m2 (OR, 1.78; P < .001). Subgroup analyses revealed higher odds of CI-AKI among patients with an eGFR less than 30 mL/ min/1.73 m2, with or without diabetes (OR, 2.12 and 1.62; P = .001 and .003, respectively), when they underwent CECT compared with noncontrast CT. Among patients with an eGFR of 30-44 mL/min/1.73 m2, the odds of CI-AKI were higher only in those with diabetes (OR, 1.83; P = .003). Patients with an eGFR less than 30 mL/min/1.73 m2 and diabetes had higher odds of 30-day dialysis (OR, 1.92; P = .005). Conclusion: Compared with noncontrast CT, CECT was associated with higher odds of AKI in patients with an eGFR of less than 30 mL/min/1.73 m2 and in patients with diabetes with an eGFR of 30-44 mL/min/1.73 m2; higher odds of 30-day dialysis were observed only in patients with diabetes with an eGFR less than 30 mL/min/1.73 m2.